QEMU env: one TMPDIR for both launch paths; the -snapshot failure in issue 68 was QEMU run by hand - #147

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/cache@v4.2.0, actions/checkout@v4.2.2, actions/setup-java@v4.7.0, actions/upload-artifact@v4.6.0, android-actions/setup-android@v3.2.2, gradle/actions/setup-gradle@v4.2.2. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/